This invention relates generally to shelving and more particularly to adjustable shelving of the "knock-down" type.
Adjustable metal shelving is well known. Such metal shelving has means provided to vertically adjust the shelving at a specified height. Many of these types have corner posts which support the flat shelving, and by means of set screws, set bolts, or the like, such as shown in U.S. Pat. No. 3,675,598, the flat shelving is positioned at the desired vertical height on the corner posts. However, it has been found that the use of such type of set screws, and the like, requires continuous loosening and tightening and therefore requires special tools, and is also subject to continuous wear, dents, loosening of the threaded parts and stripping of the threads.
An improvement on this type of adjustable metal shelving has been described in U.S. Pat. No. 3,424,111. In this patent, there is described an adjustable shelving including a flat shelf member which has corner supports secured to the flat shelf member at each of its corners. The corner supports are adapted to receive and securely hold the corner posts. The corner posts, in turn, are fitted with post supports which hold the corner supports and corner posts in a wedging secured arrangement. Additionally, the corner posts are provided with circular slots around its periphery graduated at fixed distances along the vertical dimension of the posts, and the post supports are provided with internal rib means or a ring-like band. Accordingly, the post supports are positioned with the rib means or ring-like band in a particular circular slot at a desired vertical height along the corner posts and are held clamped by means of the corner supports on the flat shelf member.
A further modification of this type of shelving is described in U.S. Pat. No. 3,523,508 which describes the details of the clamping arrangement utilizing frustro-conical sections between the corner supports and the post supports. The post supports also include an inwardly extending rib which engages within the circular indentations formed about the periphery of the corner posts at vertically spaced apart graduated locations.
A further variation of this type of shelving is also described in U.S. Pat. No. 3,604,369 which further utilizes a keyway formed in the corner supports and a corresponding wedge-like key formed as part of the post supports for engaging the keyway in the corner supports. The corner posts are also formed with the vertically spaced apart indents located at predetermined increments along the vertical dimension of the posts.
Although each of the aforementioned patents provide an improvement in adjustable shelving of the so called "knock-down" type, they all are limited in that the vertical position of the shelf along the posts is restricted to the particular location of the indentation formed in the corner posts. For example, if the graduated indentations are approximately 1 inch apart, the vertical positioning of the adjustable shelving is limited to such 1 inch increments. Although for many applications such graduated increments may be sufficient, it is frequently desired to have the shelving positioned at a vertical height which is between the graduated indentations.
It is accordingly a desirable feature to permit a secure continuous adjustable setting of the shelving along the corner posts so as to permit vertical positioning of the flat shelf at any desired height without limitation to specific graduated increments.